Cooling system for internal combustion engines



Nov. 25, 1941; s. W..RUSHMORE COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed May 9, 1941 7 Q y J INVENT Patented Nov. 25 1 941 OFFIQE 2,264,259 COOLING SYSTEM FO'R INTERNAL COMBUSTION ENGINES Samuel W. Rushmore, Plain'f ield, N. J.

Application May 9, 1941, Serial No. 392,677

7 Claims.

My present invention relates to cooling systems adapted for use with internal combustion engines and of the type adapted 'to operate by the boiling and condensing cycle and has for its object to incorporate therewith special provision for improved protection from freezing when the engine is shut down under low temperature cond'ition's.

The features of the present invention may desirably be embodied with the improved type of cooling system as shown in my Patent No. 1,851,407 of March 29, 1932, wherein, in operatioh, the water and steam from the top of the water jacket are discharged into the base of the radiator and the steam condensed in passing upwardly thereth'rough to the top tank of the radiator. From the latter the water is fed, under the action of a gear pump, to the water jacket of the engine to complete the cycle in the manner as described. A characteristic of this type of cooling system is that under certain conditions of operation, when alcohol or other anti-freeze solution is employed for winter protection, there occurs a separation of the water and anti-freeze solution between the water jacket and radiator to "a degree such as to ofier a freezing hazard at low temperature. As illustrative, with the use of alcohol in the cooling liquid, upon starting up of the motor, the first vaporization will be chiefly that of the alcohol, which boils at about 175 degrees F1, thereby transferring a substantial part of the alcohol content to the radiator and its tank. This action will accordingly leave a deficie'nc'y of the protective alcohol in the water jacket. With the use of other types of antifreeze mixtures of low specific gravity it may occur that the excess of the anti-freeze mixture remains in the jacket with the water separated therefrom by vaporization and carried over to the radiator as will be readily appreciated. In either of the referred to situations, a substantial separation of the anti-freeze fluid from the water may occur with resulting danger of damage to the motor water jacket or radiator when the engine is shut down. While the vacuum created in the water jacket when the motor cools off, with the system as described, may effect a transfer back to the jacket of suflicient alcohol to prevent freezing under certain conditions, it is found advantageous to make further provision for a back flow of the liquid from the radiator tank "to the motor water jacket so as to give positive 'insurance'of a full degree of admixture within the water jacket of water and alcohol upon shutting down or the engine, therebygiving full anti free'ze protection; this positive action being particularly important in large types of installations.

The referred to and other features and advantages of the present invention will be more fully understood by reference to the accompanying drawing wherein like reference characters are applied to the corresponding parts in the sev- 'eral views.

In the drawing:

Fig.1 is a view in side elevation, partly in section, showing the present invention incorporated with an internal combustion motor and radiator therefor.

Fig. 2 is a detailed, vertical sectional view of the return flow pipe and check valve thereof.

In the approved embodiment of the invention as here shown, the motor is conventionally indicated as including the usual crank case I and cylinder block 2, the upper parts of which are enclosed by water jacket 3. The water cooling system is conventionally indicated as including "the radiator 5, located as usual'on the same level with the motor and directly in front of it, so that the lower part of the radiator is below the level of the water jacket of the motor. The circulation of the water from the top tank 45 of the radiator is through a pipe 5 to pump 6, the latter being preferably driven from the engine at directly proportional speed. The pump is indioated as being a gear pump but this is merely to illustrate that the pump is one adapted to receive the water and force it into the water jacket against friction and any back pressure that may be caused by steaming. This pump discharges through a pipe 1, preferably into the top of the water jacket 3, whence the path of flow-is through a riser outlet 8 and downwardly extending returnpipe 9 which discharges into the bottom tank l2 of the radiator.

The pipe 1 contains a check valve ill to insure against back flow of water or steam such as might otherwise occur under operating conditions when the engine and pump are stopped. This valve located a substantial distance above the level of the pump 6 so that the output side of the pump will always be submerged in a'substantial amount of water.

In general, the bottom of the upper tank I5 is substantially below the desired initial level of water in the engine jacket 3, when the latter is full; the intake level 5a is substantially above said level and the height of the tank above the intake is such as to provide a substantial storage space into which a substantial .parftor the total positioned to connect the bottom of the radiator tank l5 with the front of the engine jacket 3,

to establish a return flow passage from the tank to the jacket. This pipe 22 is provided with the check valve 24 having valve seat 25 and co-operating swinging valve 26 pivotally supported at 21. The check valve as shown operates to close under flow or pressure from the jacket to the radiator tank and opens freely to permit flow from the tank iii to the jacket when the motor is stopped and the operating pressures reduced or cease. To give unimpeded return flow the valve is preferably of a design to be normally slightly open. Accordingly, in operation, when the motor is running there will always be suflicient pressure to efiect closing of the check valve so that no steam Or liquid will pass from the jacket to the tank [5 but upon stopping of the motor the valve will open responsive to pressure incident to difierence in liquid levels in the tank l5 and the jacket permitting a return flow from the tank to the jacket. As will be understood with the employment of alcohol for preventing freezing this return flow, incident to previous:

separation of the alcohol, will restore to the jacket fluid a substantial proportion of the protective alcohol content thereby materially to reduce danger of freezing.

The upper tank l5 as shown is provided with the usual filler closure l8 and water overflow pipe 11. A cook 20 is provided at the desired normal or cold water level in the system, which is ordinarily the top of the water jacket cavity of the engine. This cock may be open when the system is filled with water or fluid cooling medium so that the operator may observe when the desired water level is reached and may thereby be able to drain off any excess. Except during filling this cock remains closed.

Incident to this filling operation, the improved return flow pipe or connection 22 performs a further and important function in expediting the filling of the system and assuring that a proper liquid level obtains when initially filling or adding water to the system. In the operation of the cooling system as described having a boiling and condensing cycle it has sometimes been found that with the radiator vents or passages of a size to give the desired amount of resistance to outflow of steam or condensate, the down-flow of water, when the system is first charged with water or when water is to be added, may be somewhat retarded so that the operator may be led to believe that sufficient water has been put in when, in fact, there has not enough passed through the vents to completely fill the system to the desired operating level. As will be appreciated the presence of this return flow pipe 22, with the engine stopped, provides direct passage for the fluid into the jacket so that substantially true fluid level will be promptly apparent to the operator.

' The usual engine driven fan may be employed but is omitted for simplification of the disclosure.

Having described my invention, I claim:

1. An internal combustion engine having a water jacket and a water cooling system therefor including a radiator having a fluid tank associated therewith and positioned to extend above the operating fluid level of the engine jacket, means for conducting the cooling medium from the jacket through the radiator and from said tank to the jacket in a cycle and a return flow pipe connecting the upper tank and engine jacket and provided with a check valve opposing flow from the jacket to the tank.

2. An internal combustion engine having a water jacket and a water cooling system therefor including a radiator having a fluid tank associated therewith and positioned to extend above the operating fluid level of the engine jacket, means for conducting the cooling medium from the jacket through the radiator and from said tank to the jacket in a cycle and a return flow pipe connecting the tank and engine jacket and provided with a check valve opposing flow from the jacket to the tank and said valve being of the normally open type to permit free passage of fluid or return flow from the tank to the jacket when the engine is shut down.

3. An internal combustion engine having a water jacket and a water cooling system therefor including a radiator comprising a low level distributor tank, an intermediate air cooled core having relatively thin passages for upflow of fluid to be cooled and an upper tank extending above the normal level of the water in the engine jacket, a conduit means from the top of the engine jacket and discharging into the distributor tank, a water pump discharging into the engine jacket and having its intake connected to the upper tank and a return flow pipe connecting the tank and engine jacket and provided with a check valve opposing flow from the jacket to the tank.

4. An internal combustion engine having a water jacket and a cooling system therefor including a radiator comprising a low level distributor tank, an intermediate air cooled core having relatively thin passages for upflow of fluid to be cooled and an upper tank extending above the normal level of the fluid in the engine jacket, a conduit means from the top of the engine jacket and discharging into the distributor tank, a water pump discharging into the engine jacket and having its intake connected to the upper tank and a return flow pipe connecting the upper tank and engine jacket and provided with a check valve opposing flow from the jacket to the tank and said check valve being of normally open type to permit free return flow from the tank to the jacket when the engine is not running.

5. An internal combustion engine having a water jacket and a water cooling system therefor including a radiator providing a fluid reservoir extending above the operating fluid level of the engine jacket, means for conducting the cooling medium from the jacket through the radiator and from the radiator to the jacket in a cycle and a return flow conduit connecting the radiator reservoir and engine jacket and provided with a check valve opposing flow from the jacket to the radiator.

6. An internal combustion engine having a boiling and condensing cycle cooling system including an engine water jacket and a radiator providing normally separate, non-interflow, fluid reservoirs, means for circulating a cooling medium from the jacket through the radiator and a conduit connected to efiect flow of fluid from one reservoir to the other when the engine stops and said conduit being provided with a check valve for unidirectional flow therein.

'7. An internal combustion engine having a boiling and condensing cycle cooling system including an engine water jacket and a radiator providing normally separate, non-interflow, fluid reservoirs, means for circulating a cooling medium from the jacket through the radiator and a conduit connected to efiect flow of fluid from one reservoir to the other when the engine stops and said conduit being provided with a valve.

SAMUEL W. RUSHMORE. 

